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Molecular flexibility in wheat gluten proteins submitted to heating
Author(s) -
Hargreaves Jeremy,
Popineau Yves,
Le Meste Martine,
Hemminga Marcus A.
Publication year - 1995
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(95)00825-t
Subject(s) - glutenin , gluten , chemistry , prolamin , nitroxide mediated radical polymerization , wheat germ , population , electron paramagnetic resonance , radical , site directed spin labeling , wheat gluten , biophysics , biochemistry , storage protein , polymer , nuclear magnetic resonance , organic chemistry , polymerization , radical polymerization , biology , physics , demography , protein subunit , membrane , sociology , gene
Prolamin proteins are responsible for the network that gives wheat dough its viscoelastic properties. Non‐prolamin depleted gluten was prepared under conditions that preserve its functionality. Electron Spin Resonance (ESR) was used to provide information about the dynamics of the protein at temperatures between 5 and 90°C by specific spin labelling of its cysteine residues. The spectra were of a composite type, resulting from at least two populations of spin labels largely differing in molecular mobility. The correlation time of the less mobile nitroxide radicals was determined by saturation transfer ESR. Upon heating there was a transfer from the slow to the fast moving population of radicals, and an increase of mobility of this last catagory that followed the Arrhenius law. The effect of temperature on molecular flexibility was reversible. This was not the case for purified, polymerised glutenin subunits extracted from gluten. Urea created similar modifications on gluten as heat.